This invention relates to blenders and similar devices.
The preparation of food in a restaurant often involves the blending of considerable quantities of hot or cold liquids. For example, it may be necessary to blend perhaps 40 gallons of tomato sauce ingredients which are at a temperature approximately that of boiling water. A blender can be constructed with a long shaft having an upper end connected to a high speed motor and a lower end carrying blending blades. However, it is necessary to provide high speed bearings for the shaft so that it turns in a stable manner at a high speed such as 5,000 rpm, and to isolate the bearings from the hot or cold liquid to be blended. Bearings immersed in liquid can be protected by seals, but it has been found that in hot liquids the seals expand and rub hard on the shaft, which causes the seals to impart an undesirable taste to the food. Also, liquid may seep through the bearing seals and impart the undesirable taste of bearing grease to the food. A relatively compact blender which could be carried and inserted into a pot containing largely liquid material to be blended, and which could be easily operated in a safe manner to blend even hot liquids without the blender imparting a taste to the liquids, would be of great aid in the preparation of food and other materials requiring a high degree of purity.